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Evaluation of Sirolimus Dosing in Neonates and Infants With Lymphatic Disorders: A Case Series
Jordan Serio1, Sarah Gattoline1, Hailey Collier1
1Department of Pharmacy, Children's Hospital of Philadelphia, Philadelphia, PA.
Insights
The median sirolimus dose for infants with lymphatic disorders is 0.5 mg/m²/day, achieving therapeutic levels with minimal adjustments. This finding provides crucial dosing guidance for pediatric lymphatic disorder treatment.
Area of Science:
- Pediatric pharmacology
- Vascular anomalies
- Drug efficacy and safety
Background:
- Limited evidence exists for sirolimus dosing in infants with lymphatic disorders.
- Previous pediatric studies suggest higher doses (1.6 mg/m²/day) for lymphatic disorders.
Purpose of the Study:
- To determine the optimal sirolimus dose for achieving therapeutic trough concentrations in infants with lymphatic disorders.
- To establish evidence-based dosing guidelines for sirolimus in this specific pediatric population.
Main Methods:
- Retrospective review of infants (<1 year) treated with sirolimus for lymphatic disorders at Children's Hospital of Philadelphia.
- Inclusion criteria: at least 5 days of consecutive sirolimus therapy before trough concentration monitoring.
- Statistical analysis using measures of central tendency and variability.
Main Results:
- 16 infants met inclusion criteria; median initial sirolimus dose was 1 mg/m²/day.
- A median dose of 0.5 mg/m²/day achieved therapeutic trough concentrations in 87.5% of patients.
- Once-daily dosing was most common (75%), with a median of 1 dose adjustment required.
Conclusions:
- A median sirolimus dose of 0.5 mg/m²/day is effective for achieving therapeutic trough concentrations in infants with lymphatic disorders.
- Sirolimus was well-tolerated in this infant population.
- The findings support a lower, once-daily dosing strategy for infants compared to previous recommendations.
Objective:
Literature in pediatric patients suggests dosing sirolimus 1.6 mg/m2/day divided twice daily for lymphatic disorders with limited evidence available for dosing in neonates and infants. The objective of this research was to determine the sirolimus dose required to achieve therapeutic trough concentrations in infants with lymphatic disorders at Children's Hospital of Philadelphia.
Methods:
This retrospective review included patients <1 year of age at Children's Hospital of Philadelphia who were initiated on sirolimus for lymphatic disorder. Patients were included if they received at least 5 days of consecutive sirolimus therapy prior to trough concentration monitoring. Measures of central tendency and variability were used for statistical analysis.
Results:
A total of 16 patients met criteria for inclusion. The median initial sirolimus dose was 1 mg/m2/day (IQR, 0.5-1.6 mg/m2/day). Fourteen patients (87.5%) achieved therapeutic trough concentrations on a median sirolimus dose of 0.5 mg/m2/day. Dosing frequency to achieve therapeutic trough concentrations included 1 patient (6.25%) on twice daily dosing, 12 patients (75%) on once daily dosing, and 1 patient (6.25%) requiring every 48-hour dosing. The median time to first therapeutic trough was 15.5 days (IQR, 5.5-18.5 days), and patients required a median of 1 dose adjustment.
Conclusions:
A median sirolimus dose to achieve therapeutic sirolimus trough concentrations in infants with lymphatic disorders was 0.5 mg/m2/day with a median of 1 dose adjustment. Sirolimus was well tolerated in the study population.
